Some user interfaces provide an element (e.g., a text box) which is able to receive a user-defined, structured input comprising some number of inputs where the number of inputs included in the user-defined, structured input is not known by the user interface ahead of time. A command line interface is one example of such an element in a user interface. In one example, the user-defined, structured input “chmod+w file” is received by the command line interface; the user-defined, structured input can be broken down into the three inputs: “chmod,” “+w,” and “file.” That same command line interface could also receive “pwd” (where the user-defined, structured input comprises one input) or “ls-l” (where the user-defined, structured input comprises two inputs). It is not known in advance how many user inputs will be received each time and what those user inputs will be, but some information about the structure is known.
Such elements may be desirable in user interfaces because they take up less screen space (e.g., as opposed to a user interface which provides a text box dedicated for one type of user input, another text box for another user input, and so on). The downside of elements which are configured to receive a user-defined, structured input is that users may find them more difficult to work with, for example because of the rules or structure which governs a user-defined, structured input. New techniques which make such user interface elements easier to work with would be desirable.